Glossary of Children's Hospital Terms

MRI or Magnetic Resonance Imaging: A special radiology technique designed to look at internal structures of the body using magnetism, radio waves, and a computer to produce the images of body parts. The MRI scanner is a tube surrounded by a giant circular magnet. The patient is placed on a moveable bed that is inserted into the magnet. A computer processes information received, and an image is produced. The image and resolution is quite detailed and can detect tiny changes of structures within the body. Procedure for a MRI is very noisy and usually takes at least 1 hour.

MVA: Motor vehicle accident.

Malabsorption: Poor intestinal absorption of nutrients.

Malaise: A vague feeling of discomfort, one that cannot be pinned down but is often sensed as "just not right."

Malignancy: A tumor that is malignant, that is cancerous, that may invade and destroy nearby tissue and may spread (metastasize) to other parts of the body.

Meningitis: An infection of the lining of the brain, usually due to a bacterial infection but sometimes from viruses or other agents (in some cases the cause is unknown).

Metabolic: Relating to metabolism, the whole range of biochemical processes that occur within any living organism. Metabolism consists of anabolism (the buildup of substances) and catabolism (the breakdown of substances). The term "metabolic" is often used to refer specifically to the breakdown of food and its transformation into energy.

Metastatic: Refers to cancers in which there has been spreading to distant parts of the body from the original or primary site of the tumor.

Morbidity: Illness, disease.

Mortality: A fatal outcome, death.

Mortality rate: A death rate. There are a number of different types of mortality rates depending upon the population and illness being considered.

Mucous: Pertaining to mucus, a thick fluid produced by the lining of some tissues.

Myalgia: Pain in a muscle or pain in multiple muscles.

Myopathy: Muscle weakness and diseases that cause muscle weakness.

Myositis: Inflammation of muscle tissue. There are many causes of myositis, including injury, medications, and diseases.

Myringotomy: A surgically placed tiny incision in the eardrum. Any fluid behind the eardrum can then drain and usually thickened secretions can be removed. A small plastic ear tube (a tympanostomy tube) is often inserted into the eardrum. These ventilating tubes usually remain in place for 6 months to several years. Eventually, they will move out of the eardrum (extrude) and fall out of the ear canal by themselves.